This invention relates to a metering device for the precision feeding of a liquid medium, even in relatively small or minute quantities.
Oil lubricants are among the many liquids that are at times metered. In a given instance, the feeding of too little oil may place a machine at risk. However, too much oil may contaminate a product and contribute to pollution. Thus, accuracy in metering can be very important.
While accuracy in metering is generally desired, it is often difficult to attain. Air often gets into a feeding or metering system and becomes entrapped in the metering chamber. The entrapped air in the metering chamber will displace liquid medium in the measured quantity to render metering in minute quantities virtually impossible and in larger quantities inaccurate. It is generally an object of this invention to provide a metering device for a liquid medium wherein entrapment of air in the metering chamber is generally precluded to provide for more accurate metering even in minute quantities.